1. Field of the Invention
This invention relates generally to an apparatus for changing the state of a material from gas to liquid, and more particularly to an apparatus for removing water from a source of air.
2. Description of Related Art
The removal of water from air has a number of uses, including dehumidification of air for improved human comfort, industrial and commercial processes, as well as air conditioning and cooling. In recent years, the need for clean water to satisfy basic human needs has increased tremendously. This is due to increased demand for water as a result of both population growth as well as an increase in contaminants and pollution of water due to human activity and pathogens in water. In addition, population growth and economic activities have resulted in increased habitation of dry, arid regions of the planet. These regions often times fall short of an adequate supply of drinking water.
There have been various attempts in the prior art at removing water from air. The most prevalent dehumidification technology uses the condensation of moisture by cooling the air below the saturation temperature by way of the thermodynamic processes of compression and expansion of a coolant. The modern air conditioner, for example, uses this technology. The invention of the air conditioner by Willis Haviland Carrier in upstate New York in 1906 was described in U.S. Pat. No. 808,897 entitled “Apparatus for Treating Air”. The basic “Rational Psychrometric Formulae” of Willis Haviland Carrier, as disclosed to the American Society of Mechanical Engineers in 1911, formed the basis of all fundamental calculations for the air conditioning industry, and is still in use today. The techniques invented by Carrier are still by far the most common techniques for removing water from air. Unfortunately, these techniques are also energy intensive, creating pollution through the production of electric power required to run the compressors and refrigeration equipment and also contributing to global climate change. An example of the use of a refrigerant condenser to generate water from air is U.S. Pat. No. 5,149,446 to Reidy, entitled “Potable Water Generator”.
Another technique in the prior art to remove water from air is the adsorption of water molecules by a chemical desiccant material. This process requires a regeneration cycle, which is both energy intensive and mechanically complex.
An area of recent interest is that of electrostatic dehumidification technology. Electrostatic collection of water from air uses the basic premise that a water molecule has a dipole moment, and can also be charged. In the presence of a strong electric field, the water molecule will migrate in a predictable direction, and thus be removed from the air. It is noted that the dipole gradient force of the water molecule is relatively weak, but the acquisition of a charge will allow the coulomb force to dominate and react to a strong electric field. Attempts at electrostatic dehumidification technology have used techniques similar to the control of air or liquid flow or the filtering of air using electrostatic principles. Such techniques are disclosed, for example, by Krichtafovitch et al in United States Patent Application Publication US 2006/0226787 A1 entitled “Electrostatic Fluid Accelerator For And Method Of Controlling a Fluid Flow”, the entire disclosure of which is incorporated herein by reference. Many of the electrostatic air dehumidifier projects use corona discharge similar to that used in electrostatic filters for removal of particulate matter from an air stream. Such a project was the Corona Air Pump Project submitted to the American Public Power Association and undertaken by Nets Jewell-Larsen at the University of Washington in Seattle, Wash. Unfortunately, the final report on this project dated Feb. 28, 2005 stated that the investigation was unsuccessful at developing a working electrostatic dehumidification prototype for molecular-water level dehumidification. The use of the action of a strong electric field on water molecules, and the interaction of forces to cause the migration of water molecules or droplets, is little understood, and is the topic of research.
It is therefore an object of the present invention to provide an apparatus that removes water from air without the use of energy intensive mechanical cooling. It is another object of the present invention to provide an apparatus that removes water from air without the use of chemical desiccants. It is yet another object of the present invention to provide an apparatus that removes water from air using electrostatic principles but without corona discharge. It is yet another object of the present invention to provide a highly energy efficient apparatus for removing water from air.